Four small excavation squares (each 2 × 2 m; TW1, TW2, QE, TN-Z; Fig. 1) were opened inside the harbor of Caesarea in areas that had not been disturbed by previous excavations. The object of the excavation was to detect strata in the harbor that were identified as evidence of tsunami stratification in previous studies (Reinhardt et al. 2006; Raban 2008; Goodman-Tchernov et al. 2009) and in an excavation in 2010 (Goodman-Tchernov et al. 2021), which took place outside the harbor on land and sea. The most recent stratification was dated to the tsunami event that occurred in 551 CE, and the earlier one was dated to 114 CE. The excavation squares complete a sequence of probes previously excavated by A. Raban between Area QN and Areas TW and TN (Raban 2009).
Square TW1 (Fig. 2). An excavation frame (2 × 2 m; excavation depth 2.6–3.0 m below mean sea level [bmsl]) was placed c. 4 m northwest of the sunken rectangular tower. Two strata were revealed. The upper stratum was the surface layer (L101; 2.6–2.7 m bmsl), which included shells, worn potsherds, modern material and building rubble at the bottom of the stratum. A layer of sand (L102) uncovered beneath the building rubble included worn potsherds, fragments of glassware and roof tiles and modern finds. Beneath this layer (3 m bmsl) lay the kurkar bedrock (L103).
Square TW2 (Fig. 3). The excavation (2 × 4 m; 1.4–2.6 m bmsl), opened next to the rectangular tower, revealed two strata. The upper stratum was the surface layer (L201; thickness 0.2 m), which was covered with small and medium-sized kurkar stones, shells and modern material. A mixed layer of collapsed stones and modern material (L202; 2.0–2.6 m bmsl) was revealed beneath this stratum. The foundation courses of the rectangular tower were found resting on kurkar bedrock (L203; 2.6 m bmsl). A probe dug in previous excavations was found at the foot of the rectangular tower; dressed building stones from the collapsed upper courses of the tower lay beside it.
Square QE was opened c. 10 m northwest of Square TW1. The surface layer of the excavation (2.4 m bmsl) was characterized by a thin layer (thickness 0.1 m) of sand, shells and worn potsherds. A layer of pebbles was uncovered beneath the surface layer, and the bedrock was found at a depth of 2.8 m bmsl. No ancient remains were found.
Square TN-Z (Fig. 4). The location of the excavation square, between the rectangular tower and the round tower, was chosen on the assumption that the towers provided some protection, thus reducing the disturbance of sedimentary layers. Eight superimposed strata were uncovered (L401–L408), presented below from top to bottom. Stratum 401, the surface layer (2.1 m bmsl), contained large and medium-sized stones, pebbles, sand, many roof-tile fragments and modern debris. Stratum 402 (thickness 5 cm; 2.3 m bmsl) contained gray loam and a few potsherds. In Stratum 403 (2.35 m bmsl) the sediment had a different color and was composed of a layer of silt containing potsherds, nearly all from the Byzantine period (fifth–seventh centuries CE), including imported bowls (Fig. 5), two of which (No. 2 and 7) bear incised decoration on the body, as well as a few metal objects: copper coins and small rectangular lead fishing-net weights. One of the weights bears lines embossed crosswise from the foundry mold (Fig. 6). This stratum also yielded modern finds, including pottery and a musket bullet. Animal bones and abundant organic material were also found. Stratum 404 (2.45 m bmsl) contained silt, many Byzantine potsherds, and organic matter. Stratum 405 (2.55 m bmsl) contained dressed stones and numerous fragments of pottery vessels dating mostly from the Byzantine period (fourth–seventh centuries CE), including bowls, one of which was found intact and bears an incised decoration under the rim (Fig. 7:1), casseroles (Fig. 7:2, 3), bag-shaped jars (Fig. 7:4), Gaza Ware jars (Fig. 7:5, 6) and jugs (Fig. 7:7–9). The stratification and the pottery types are similar to those in Stratum 404. Stratum 406 (2.65 m bmsl) consisted of a thin horizon of clean sand with no pottery (thickness c. 7 cm). Stratum 407 (2.72 m bmsl) comprised a horizon of sand of a different color containing many shell fragments. Stratum 408 (2.87 m bmsl) included fieldstones and pottery.
Following summer and winter storms, the strata in Squares TW1, TW2 and QE had been intermixed and included modern material and could therefore not be dated. In Square TN-Z, the transition from Strata 404 and 405—characterized by abundant potsherds, animal bones and organic matter and dated to the Byzantine period—to the clean layer of sand in Stratum 406 is clearly visible. According to excavation director Goodman-Chernov, this transition marks the tsunami event that occurred in the Byzantine period, in 551 CE, which is documented in historical sources (Amiran, Arieh and Turcotte 1994).